Preparation and performance analysis of active packaging PET films combining oxygen scavenging with barrier properties for shelf life extension of sensitive foods

The aim of this work was to prepare and evaluate the scavenging performance and the oxygen absorption kinetics of active food packaging PET films, containing a novel auto-activated, copolyester-based oxygen scavenger, which includes in its formulation also a copolyamide phase for enhanced passive gas barrier. Films at three different scavenger content (5%, 10% and 20% by weght) were produced by cast film technology, analyzed in terms of morphology and scavenging activity and tested to verify their effectiveness in preserving the quality of oxygen sensitive foods, performing preliminary shelf life tests on slices of cooked ham. The results highlighted that the films at 10% scavenger loading showed the most homogeneous dispersion and distribution of the reactive domains inside the PET matrix, the best scavenging performances and high potential in prolonging the shelf life of sensitive food matrices

Sustainable Active PET Films by Functionalization With Antimicrobial Bio-Coatings

The realization of antimicrobial films through the incorporation of active agents into a polymer matrix is a promising alternative to the direct addition of antimicrobials into the food matrix. To this aim, the goal of this work was to develop a sustainable, food packaging solution with antimicrobial effectiveness and high functional performance, based on Ethyl-Nα-dodecanoyl-L-arginate (LAE). Active biodegradable coatings, easy soluble to be removed, were realized by spreading a Polylactic acid/LAE coating solution, at different antimicrobial concentration (from 0 to 20%), on a recyclable Polyethylene-terephthalate substrate. The antimicrobial activity of the multilayer films was tested in vitro against E.Coli CECT 434 strain as pathogenic agent in liquid culture media. Moreover, the LAE chemical interaction with the PLA matrix was investigated, as well as its effect on the adhesion, wetting, optical and barrier properties of the films. The results pointed out that that the minimum LAE concentration incorporated already guarantees an antimicrobial activity comparable to commercial antimicrobial packaging solutions, and that, among the systems investigated, 10% LAE is the minimum concentration guaranteeing total inhibition without significantly altering the functionalities of the developed systems

Coextrusion Film Blowing of PHB, PLA and PBAT-based Blends for the Production of Biodegradable Food Packages

In this work, melt blending and co-extrusion techniques have been investigated as functionalization strategies to realize bilayer biodegradable films suitable for food packaging applications, combining enhanced barrier performance, good heat sealability and ductility. The ductile, heat sealable inner layer was realized by mixing Ecovio, a commercial blend based on polylactide (PLA) and polybutylene adipate terephthalate (PBAT) with an amorphous PLA grade; the outer barrier layer, on its side, was realized by blending poly(hydroxybutyrate) (PHB) with a semicrystalline PLA grade. Three different structures were realized changing the relative thicknesses of the two layers, and were characterized for their surface wettability, O2 barrier, heat-sealability and tensile properties. The results highlighted the impact of the bilayer films layout on the functional performance, and pointed out the attractiveness of the developed structures for food packaging applications where barrier to oxygen is critical to reduce oxidative processes

Sustainable food packaging: An updated definition following a holistic approach

publishedVersio

Optimized EGFR blockade strategies in <i>EGFR</i> addicted gastroesophageal adenocarcinomas

Purpose: Gastric and gastroesophageal adenocarcinomas represent the third leading cause of cancer mortality worldwide. Despite significant therapeutic improvement, the outcome of patients with advanced gastroesophageal adenocarcinoma is poor. Randomized clinical trials failed to show a significant survival benefit in molecularly unselected patients with advanced gastroesophageal adenocarcinoma treated with anti-EGFR agents.Experimental Design: We performed analyses on four cohorts: IRCC (570 patients), Foundation Medicine, Inc. (9,397 patients), COG (214 patients), and the Fondazione IRCCS Istituto Nazionale dei Tumori (206 patients). Preclinical trials were conducted in patient-derived xenografts (PDX).Results: The analysis of different gastroesophageal adenocarcinoma patient cohorts suggests that EGFR amplification drives aggressive behavior and poor prognosis. We also observed that EGFR inhibitors are active in patients with EGFR copy-number gain and that coamplification of other receptor tyrosine kinases or KRAS is associated with worse response. Preclinical trials performed on EGFR-amplified gastroesophageal adenocarcinoma PDX models revealed that the combination of an EGFR mAb and an EGFR tyrosine kinase inhibitor (TKI) was more effective than each monotherapy and resulted in a deeper and durable response. In a highly EGFR-amplified nonresponding PDX, where resistance to EGFR drugs was due to inactivation of the TSC2 tumor suppressor, cotreatment with the mTOR inhibitor everolimus restored sensitivity to EGFR inhibition.Conclusions: This study underscores EGFR as a potential therapeutic target in gastric cancer and identifies the combination of an EGFR TKI and a mAb as an effective therapeutic approach. Finally, it recognizes mTOR pathway activation as a novel mechanism of primary resistance that can be overcome by the combination of EGFR and mTOR inhibitors

A Major Role for Side-Chain Polyglutamine Hydrogen Bonding in Irreversible Ataxin-3 Aggregation

The protein ataxin-3 consists of an N-terminal globular Josephin domain (JD) and an unstructured C-terminal region containing a stretch of consecutive glutamines that triggers the neurodegenerative disorder spinocerebellar ataxia type 3, when it is expanded beyond a critical threshold. The disease results from misfolding and aggregation, although the pathway and structure of the aggregation intermediates are not fully understood. In order to provide insight into the mechanism of the process, we monitored the aggregation of a normal (AT3Q24) ataxin-3, an expanded (AT3Q55) ataxin-3, and the JD in isolation. We observed that all of them aggregated, although the latter did so at a much slower rate. Furthermore, the expanded AT3Q55 displayed a substantially different behavior with respect to the two other variants in that at the latest stages of the process it was the only one that did the following: i) lost its reactivity towards an anti-oligomer antibody, ii) generated SDS-insoluble aggregates, iii) gave rise to bundles of elongated fibrils, and iv) displayed two additional bands at 1604 and 1656 cm−1 in FTIR spectroscopy. Although these were previously observed in other aggregated polyglutamine proteins, no one has assigned them unambiguously, yet. By H/D exchange experiments we show for the first time that they can be ascribed to glutamine side-chain hydrogen bonding, which is therefore the hallmark of irreversibly SDS-insoluble aggregated protein. FTIR spectra also showed that main-chain intermolecular hydrogen bonding preceded that of glutamine side-chains, which suggests that the former favors the latter by reorganizing backbone geometry

Evaluation and modeling of scavenging performances of active multilayer PET based films for food preservation

This work deals with the design, production and evaluation of the effectiveness of multilayer active systems based on PET, suitable for food packaging applications. Symmetrical 3-layer structures were produced by using a cast co-extruder laboratory-scale equipment. The oxygen scavenger (OS), copolyester based and approved for direct food contact, was added to the central layer. Two multilayer active films were obtained by keeping constant the thickness of the active layer and with different thicknesses of the inert layers. Active single layer and neat films were also produced for comparison. Oxygen absorption measurements in continuous were performed by means of a luminescence lifetime detection device. The scavenging performances, in terms of scavenging activity, exhaustion time and residual oxygen concentration in the package were investigated; in particular, their variation as function of the thickness variation of the inert layers was analysed. Preliminary shelf life tests were also conduced on Brassica oleracea florets, in order to point out the effectiveness of the OS systems in inhibiting vegetables senescence. Finally, a mathematical model, developed during previous studies, was applied to the data set in order to validate it and verify its effectiveness in predicting the transport phenomena occurring in the multilayer active systems

Understanding the Impact of Biodegradable Microplastics on Living Organisms Entering the Food Chain: A Review

Microplastics (MPs) pollution has emerged as one of the world’s most serious environmental issues, with harmful consequences for ecosystems and human health. One proposed solution to their accumulation in the environment is the replacement of nondegradable plastics with biodegradable ones. However, due to the lack of true biodegradability in some ecosystems, they also give rise to biodegradable microplastics (BioMPs) that negatively impact different ecosystems and living organisms. This review summarizes the current literature on the impact of BioMPs on some organisms—higher plants and fish—relevant to the food chain. Concerning the higher plants, the adverse effects of BioMPs on seed germination, plant biomass growth, penetration of nutrients through roots, oxidative stress, and changes in soil properties, all leading to reduced agricultural yield, have been critically discussed. Concerning fish, it emerged that BioMPs are more likely to be ingested than nonbiodegradable ones and accumulate in the animal’s body, leading to impaired skeletal development, oxidative stress, and behavioral changes. Therefore, based on the reviewed pioneering literature, biodegradable plastics seem to be a new threat to environmental health rather than an effective solution to counteract MP pollution, even if serious knowledge gaps in this field highlight the need for additional rigorous investigations to understand the potential risks associated to BioMPs